A ROM of an intelligent terminal stores an operating system. The ROM is short for read-only memory (Read-Only Memory), and is a solid-state semiconductor memory from which only prestored data can be read. A characteristic of the ROM is that once data is stored, the data cannot be changed or deleted, and the data does not disappear due to power off. Generally, for system security, data is not allowed to be erased. Therefore, the operating system stored in the ROM can only be read but cannot be changed or erased. However, to implement system upgrade, a ROM can be modified and erased by using a program on a computer. “ROM flashing” people are talking about is ROM erasing. Alternatively, during system upgrade, an upgrade package can be downloaded to a storage device of a mobile phone, and then the upgrade package is installed on the intelligent terminal in a restart process after the upgrade package is verified, thereby updating information in a ROM. Herein, installation packages used for ROM flashing or system upgrade, such as a system update program package, a system upgrade program package, and a system transplantation program package that are used for a ROM of a mobile device, are collectively referred to as a ROM installation package.
To avoid a loss caused by a lost mobile phone, an operating system of the mobile terminal provides a lock screen function. A user may set a text password, a gesture password, a fingerprint password, a facial expression password, or a voice password for unlocking of a screen, so that other people have difficulties in unlocking the screen to perform an operation on the mobile terminal. This preliminarily protects data stored in an internal memory of the mobile terminal, but the screen still cannot be prevented from being unlocked through ROM flashing.
Some privacy protection or antitheft application software such as some security software may further be installed in a mobile terminal. An alternate phone number may be preset on the mobile terminal by using the software. When another SIM card is put into the lost mobile terminal, the mobile terminal automatically sends an SMS message to the alternate phone number, to inform the alternate phone number of a new phone number of the lost mobile terminal. After learning of the new phone number, the owner can send an SMS message to the new phone number to perform some particular operations, for example, perform a positioning operation. After the mobile terminal is lost, a thief usually prevents, through ROM flashing, the owner from retrieving the lost mobile terminal. When such security software or plugin components having a relatively high level are revoked or removed through ROM flashing, after another SIM card is put into the lost mobile terminal, because the security software is removed, a notification SMS message cannot be sent to the alternate phone number, and a new phone number of the lost mobile terminal with the changed SIM card cannot be learned of either. Consequently, the owner cannot send an SMS message notification to the lost mobile terminal, and antitheft functions such as positioning also become invalid.